When Jun returns home, he is greeted by his mother Yukari, who has just stepped out of the bath, wearing nothing but a single bath towel. Her careless attitude—thinking that it might be somewhat acceptable in front of her own son—ends up drastically altering the fate of their mother-son relationship. Suddenly, the towel slips down, revealing a pair of pure white buttocks that starkly contrast her tanned skin, looking as if she’s wearing pristine white underwear. For Jun, who has only ever known her sun-kissed body, the sight is utterly shocking—and instantly captivates him.